Bedridden patients who have to maintain a substantially motionless position for prolonged periods of time develop bedsores on the skin. These sores, referred to in medical terms as Decubitus Ulcers, are painful, hard to heal, and create conditions for further infection. Ulcer formations of this type are produced in most cases because the pressure exerted upon the skin surfaces under the bony prominences of the patient which bear most of the weight of the patient when the body of the patient presses against the ordinary mattress or other body support and obstructs the circulation of blood in the capillaries directly under these surfaces.
Certain types of body support devices which overlie the conventional mattress in a hospital bed have been constructed to minimize ulcer formation.
One such device is disclosed in copending application Ser. No. 295,504 filed 4/14/81 now U.S. Pat. No. 4,422,194 and assigned to the assignee of the present application. This device is a body support which can be filled with water or air. This support employs a first plastic section having oppositely disposed inner and outer surfaces. The outer surface is disposed above the inner surface and permanently defines a plurality of closely spaced raised regions of like size and contour which are interconnected by channels disposed below the walls of the regions. The inner surface of the first section permanently defines a like plurality of deep recesses, each deep recess constituting the inside of a corresponding region. The deep recesses are interconnected by shallow recesses, each shallow recess constituting the inside of a corresponding channel.
A second plastic section is sealed to the inner surface of the first section in a manner in which said deep and shallow recesses communicate with each other. A flexible hollow tube is disposed around the periphery of said sections and is secured thereto. The tube has an outer wall with openings which connect the tube interior to said shallow recesses. The tube and sections are sealed to each other in a leak-proof manner to prevent leakage of air or water between the interior of the tube and sections and the outside thereof.
This combination of tubes and sections thus has a hollow interior with deep and shallow recesses and tube interior being interconnected. In use, the interior is completely filled with water or air.
When a patient lies upon the device, the various raised regions conform independently without stretch tension to the body contour and, because of the intercommunicating hollow regions, the shallow channels and tube distribute the water or air as required. As the patient shifts in bodily position, the water or air movement adjusts the shape of the device accordingly.
The raised regions are depressed when conforming to the body contour and spread sideways to close the gaps therebetween, thus providing a continuous support between the spread regions and the body of the patient. Unlike the prior art devices, the top portions of the raised regions are not subjected to appreciable stretch-tension forces since the tube substantially eliminates sideways deformation of the raised regions which would otherwise produce such forces with the resultant adverse effects previously described. The use of the tube filled with water or air permits the raised regions that are not underneath the body to remain upright whereby the surface stretch in the rest of the raised regions under the body stretch-tension is minimized, and the pressure on the skin is also minimized, thus minimizing ulcer formation.
In another copending application, Ser. No. 06/543143 filed 10/18/83 and also assigned to the assignee of the present application, a similar tube and section structure is made even more effective in reducing ulcer formation by filling the central sections with water at the same time the peripheral tube is filled with air.
While the structures described above are very effective in minimizing ulcers, they are relatively heavy. When a patient lies on one of these structures which in turn overlies the mattress in a hospital bed and one end of the mattress is raised by operating the hospital bed mechanism the patient and the structure will slide downward toward the lower end of the mattress. This movement seriously impairs the effectiveness of the structure in minimizing ulcer formation and of course can cause the patient other discomfort.
The present invention eliminates such undesired downwardly sliding movement.